山区曲线桥梁设计问题的探讨

受到道路整体线形的布置和地形的阻碍，山区桥梁在设计过程中直线线形通常不能满足指标要求，所以曲线桥的发展越来越受到人们的关注。直线桥和曲线桥的设计要求大相径庭，针对曲线桥的设计进行了分析研究。主要研究了曲线桥的受力方式、曲线桥的分析方法及不同曲率下桥梁的空间分析。通过利用Midas FEA桥梁建立实体模型，计算分析了曲率半径对支座反力、主梁内外侧挠度差值及应力差值的影响。对桥梁的设计工作提供了相应的理论依据。     

高等级公路路基拓宽工程处治技术探讨

该文针对高等级公路路基拓宽工程常见的病害,将拓宽路基进行模型简化,通过对实际项目进行计算分析,提出了加强新老路基结合面的处治,路基加筋,拓宽部分路基地基处理,拓宽路基填料及压实度控制等具体处治措施来减小新老路基交界面产生的沉降差。其成果对今后路基拓宽工程实际项目中处治措施的选择、设计和施工具有重要的借鉴和指导意义。     

基于振型的传感器优化布置与损伤识别

为了对现役桥梁进行正确的状态评估,并对出现的损伤状况进行识别,文中基于有效独立法研究了传感器的优化布置,并采用柔度差法模拟了损伤识别情况.通过算例验证了该方法的有效性.     

南美地区大潮差条件下海港工程设计施工

针对部分海域海港工程建设中潮差较大的问题,设计采取改梁板为下层全预制结构、改护舷挡板为钢结构、试验取消剪力键的方法来减少水上作业时间,并用组合桩解决浪溅区的防腐难题;在施工方面,根据水上施工环境的窗口期分析和潮位预报,提出须乘潮靠港并及时松紧缆,推荐采用随潮差转动的跳板驳和浮码头,借潮起重安装钢栈桥,采用自升式平台避潮和根据潮差采用不同抛石工艺等方法解决大潮差下水上施工的难题,可为大潮差条件下的工程建设提供借鉴。     

On the fluid-structure response of elastic-plastic ship sides subjected to impact loads

This paper presents a simplified numerical model capable of analysing the interaction between the structural dynamic response of elastic-plastic struck plate wall of a fluid tank subjected to wedge impact and the resulting fluid motion. The Variational Finite Difference Method (VFDM) is applied to analyse the structural dynamics of the struck plate and 2-D linear potential flow theory is used to study the resulting fluid motion and its effects on the structural dynamics of the struck plate. Experiments of a wedge indenter impacting with both empty and 90% filled tanks are carried out to study the structural deformation of the struck plate. The accuracy of the developed numerical model is validated with published results and experimental results, and good agreement is achieved. Through the comparison of the impact behaviour of empty and partially filled water tank, it is found that the resulting water motion helps to reduce the structural deformation of the struck plate since part of the impact energy is dissipated by the resulting water motion. Parametric studies are performed to investigate the effect of impact velocity and water level on the structural dynamics of the struck plate of a partially filled water tank. A case study is also conducted to demonstrate the potential application of the proposed method in analysing ship-ice impact problems.     

Solving Electromagnetism Differential Equations Based on Random Walk

An approach of solving the finite difference equations with Monte Carlo method was presented. The accuracy of algorithm is guaranteed by the Central Limit Theorem. The computation of the value on each single node is independent of each other, which makes it easy to realize the algorithm in parallel processing and greatly improves the efficiency while dealing with local area computation. As long as different kinds of boundary conditions are statistics modeled ,wide applications can the be made where the finite difference method is of competence.     

盾构隧道近接浅埋式矩形隧道合理净距的研究

以正在建设中的深圳地铁11号线南山至前海湾站小净距重叠区间隧道为研究对象,按先明挖修建桂庙路矩形闭合框架隧道,后进行地铁盾构推进的顺序,采用FLAC有限差分程序对小净距重叠隧道进行弹塑性分析,对多种工况下的围岩位移、夹岩应力、塑性区分布等进行分析,提出矩形闭合框架隧道的管幕作用,其作用影响范围大致沿Mohr-Coulomb模型剪切破坏面(45°+φ/2)的角度,以矩形隧道宽为底边的闭合等腰三角形区域。在此区域内的地下结构均受管幕作用的影响,且距离矩形闭合框架隧道越近管幕作用越明显,在综合考虑了矩形隧道管幕作用和隧道之间近接效应的情况下,确定隧道之间的合理净距。     

铁路建设项目甲供物资价差计算方法优选

铁路建设项目重要物资实行甲供方式后,其价差可上报要求批准追加工程造价,如何合理选择价差计算方法对风险合理分摊、优化工程造价控制至关重要.此文提出4种主要的甲供物资价差调整计算方法,对其中3种方法进行深入阐述和分析,提出在既有方法基础上的优先方案,供实际工作中具体运用.     

高填方涵洞土压力与填土沉降差关系分析

结合工程实际,通过对两个试验段的对比,分析了涵洞土压力与填土沉降差关系,总结了形成土拱的条件,对类似工程设计与施工有一定借鉴与指导。     

地震勘探反问题的差分算子法

本文针对地震勘探中的一维波动方程反问题的数值解法,给出了一个算子方程T(P)=F,较详细讨论了算子T的性质,同时给出了解上述方程的方法和算例。